Disposal of worn vehicle tires is a problem of particular concern. Due to their shape, intact tires tend to collect standing water, creating a breeding ground for unwanted insects. Also, when buried in a landfill, intact tires tend to trap gas bubbles, which makes them buoyantly rise within a landfill, creating problems. These concerns are well known, and have been addressed by cutting tires into pieces that do not readily trap water or air. Many landfill facilities either refuse to accept whole tires, or charge several times more per pound to receive whole tires than cut tires.
Existing tire cutters use several approaches. Tire shredders operate to chop tires into a multitude of small pieces, but at significant operating cost. Shredders require an inordinate amount of energy, as tires are inherently tough, particularly due to the very strong steel or synthetic reinforcing fibers used, as well as the thick wire or cable used to reinforce the tire bead. These materials cause substantial wear on the rotary shear blades used. Such shredders are very large and expensive, making them impractical for widespread use. Accordingly, there are significant shipping costs to transfer tires to the nearest shredder facility, because they are generally few and far between.
Other tire cutters partially cut tires into segments that are more tolerably disposed of. These may be radial cuts, a circumferential "bagel" cut about the midline of the tread, or circumferential sidewall cuts that remove the sidewalls from the tread band.
Heavy shears have been used, but are too large and expensive for small scale operations, and are subject to significant wear making it difficult to hold necessary sharpness and tolerances, especially due to the difficulty of cutting bead wires. Sidewall cuts have been performed with knife blade cutters, but this is believed to be unsuitable for all but the lightest passenger car tires. Other cutters employ rapidly rotating saw-type blades that dull readily, or use rotary cutters that operate by shearing tire materials, with the attendant wear and tolerance difficulties.
The embodiment disclosed herein overcomes these disadvantages by providing a tire cutter apparatus including a rotatable anvil wheel assembly and a cutter wheel assembly connected to a frame. The anvil wheel assembly has an anvil wheel with a smooth circumferential anvil surface. The cutter wheel assembly includes a cutter wheel having a peripheral edge. The cutter wheel assembly and the anvil wheel assembly are movable between a closed position in which the cutter wheel edge is adjacent the anvil surface to define a cutting site, and an open position in which the cutter wheel edge and the anvil surface are spaced apart. A gripping wheel having an articulated peripheral edge is connected to the cutter wheel assembly and/or to the anvil wheel assembly, so that the gripping wheel engages a portion of a tire to move the tire through the cutting site. The apparatus may be a compression cutter defining a nip, and multiple overlapping gripping wheels may be driven to drive the tire through the cutter.